SPRequireUnique CrossList Functionality

Just wondering if there is an option or someone has implemented modified SPRequireUnique function enabled to work on different lists. What I mean is... I want to check unique value within List B where columnStaticName (input column)
is on the List A on the NewForm.aspx.

There's nothing specific in SPServices for this, but you can use SPServices as your toolset to accomplish it. You can lookup the values in list B using GetListItems, either as the user types or upon form submission using PreSaveAction.

I am not a programmer and don’t know if I am on right way to accomplish this task. I took your advice and try to implement using GetListItems and PreSaveAction but this don’t work for me. Probably my coding is rubbish.

In your PreSaveAction, you'll want to get any items which match the value you want to check. Right now, you don't have any filtering; you're just getting all of the values. If you return false from PreSaveAction, the form won't save. You will want to give
the user some sort of message, of course, so that they know what they need to fix.